The overarching goal of my program of research is to improve outcomes in patients with chronic disease by optimizing treatment for sleep disorders. Continuous positive airway pressure (CPAP) therapy is an effective treatment for obstructive sleep apnea (OSA), but adherence is poor. Motivational enhancement (ME) therapy is the most promising approach, to date, for improving adherence to CPAP, but the intervention would be optimized by added support for patients and alternative strategies for intervention delivery. Significant others (SO) are likely to exert positive and negative effects on the patient's adoption and use of CPAP and are frequently described as the greatest source of social support for patients with chronic illness. Beginning the intervention before CPAP initiation would capitalize on the teachable moment shortly following diagnosis when motivation and social support may be most essential. The first aim of the research plan is to explore critical factors for adoption and use of CPAP by both patients and SOs using qualitative research methods (focus groups); and to modify a brief motivational intervention for CPAP based on information obtained from the focus groups and incorporation of SOs in the intervention sessions. The second aim is to conduct a randomized controlled pilot study to examine the effects of the modified motivational intervention on CPAP adherence and the relationship between CPAP adherence and health outcomes (e.g., daytime sleepiness, sleep-related functional status, self-reported medication adherence, and blood pressure). Patients in the pilot study will be randomized to the intervention, attention control, or standard clinical care group. To achieve the goals of this research plan and my long-term goal of becoming an independent researcher developing behavioral interventions targeting adherence to sleep disorder treatments, I require further training in the following areas: (1) sleep disorder treatments, (2) behavioral intervention development incorporating motivational interviewing techniques and couple level approaches, (3) CPAP adherence methodology, assessment, and analysis, and (4) methodological and statistical techniques in designing and conducting randomized clinical trials. This proposal offers an innovative approach to improving CPAP adherence and has the potential to make a significant impact on current intervention strategies for improving adherence to an efficacious treatment in an increasingly prevalent public health problem.